1. Field of the Invention
This invention relates generally to a flushing mechanism for use in toilet flushing applications. More particularly, the invention relates to a low water volume, pressurized water closet reservoir.
2. Background Art
A typical flushing system includes a tank connected to a toilet bowl. The tank holds approximately three to five gallons of water and is positioned above the level of the bowl. In such a system, flushing of the bowl is achieved by breaking a seal at the bottom of the tank and releasing the water contained within the tank. The weight of the water due to gravity generates a high velocity flow that then carries bowl water and waste into the sewer line.
In this type of system, the weight of the water alone is used to effect the flushing and replenishing of the bowl, and a minimum of three and a half to four gallons of water are typically required to flush the bowl. Because of the heightened concern caused by decreasing water supplies and the consequent need for water conservation measures, there is a trend to replace gravity-fed water closets with pressurized water closets which utilize a lower volume of water per flush. These pressurized water closets typically have a pressurized reservoir to hold the flush water, and a valve which is actuatable by the user to discharge the pressurized water into the bowl and thereby carry the bowl water into the sewer line. The pressurized water closet of this sort provides a flushing action that is comparable to that which occurs in a gravity-fed water closet, yet it does so by utilizing a much smaller volume of water.
Although pressurized water closets significantly reduce the amount of water used per flush, closets of this type also suffer from several drawbacks. One problem encountered with a pressurized water closet is that the seals used in the pressurized reservoir can deteriorate and fail when the reservoir is overpressurized. Seal failure results in water leaking from the reservoir, which can result not only in significant property damage to floors and walls, but also in the waste of water.
To assist in extending the useful life of pressurized water closets, pressure reducing valves are utilized. The pressure reduction valve is positioned between the water supply and intake port of the pressurized reservoir. This reduces the pressure of the water entering the reservoir. As a result, the components of the flushing mechanism and seals of the reservoir are spared some of the wear typically experienced under higher-pressure use.
The use of pressure-limiting valves on the intake line of the water entering the water closet has, however, led to a related problem. The same deterioration occurring within the water closet seals, also can occur within the pressure-limiting valve and eventually the pressure-limiting valve may break down allowing excessive pressure to build up within the pressurized reservoir. If this occurs, the higher pressure may also eventually break down the seals in the pressurized reservoir causing the reservoir to leak.
Alternative mechanisms to reduce excess pressure within the reservoir have also been proposed. One such mechanism will automatically sense the presence of excessive pressure within the reservoir, and then relieve the pressure by releasing water into the bowl. Although this approach insures that the reservoir is never subjected to excessive pressures, it does so by continuously discharging water. Thus, the approach may not be satisfactory in areas where water conservation is a concern.